Of relatively small, single-phase induction motors, a shading coil type induction motor is the simplest in construction but not capable of reversible rotation. In general, it is a condenser type induction motor (a condenser motor) that is widely employed as a single-phase, AC reversible motor with an output of less than 1 kW, but this type of motor requires a large condenser to be mounted on the outside thereof; this inevitably leads to a bulky and heavy structure and, in addition, poses problems of the selection of a position for mounting the condenser and of increasing the manufacturing cost.